Cooling device for electronic components

ABSTRACT

A fluid heat exchanger includes: a base, a heat pipe including an evaporator portion thermally coupled to the base and a condenser portion; a coolant block portion thermally coupled to the condenser portion of the heat pipe, the coolant block portion including a liquid tight passage extending from a passage inlet to a passage outlet.

FIELD

The present invention relates to a cooling device for electrical andelectronic components and, in particular, a liquid heat exchanger.

BACKGROUND

Heat generating electrical or electrical components include for examplememory chips, CPUs, voltage regulators, drivers, etc. and generate heatthat is deleterious to their operation and the operation of other systemcomponents.

Fluid heat exchangers are used to conduct heat away from heat generatingelectrical or electrical components and into a passing fluid such asair. A fluid heat exchanger generally may include a thermal plate and aheat-dissipating portion. The thermal plate is installed in thermalcommunication with a heat source such as directly or indirectly on aheat generating electrical or electronic component. The heat-dissipatingportion is thermally coupled to the thermal plate to conduct heat energytherefrom. Coolant fluid passes through the heat-dissipating portion toaccept heat energy therefrom. Where liquid coolant fluid is used, forexample, the liquid is pumped through a block, sometimes called a “waterblock”, forming at least part of the heat dissipating portion where theliquid accepts the heat energy and then the heated liquid is pumped to aheat sink located at some distance from the block. It will beappreciated that various liquid coolants are known such as freon, water,alcohols, glycols, etc.

General information concerning fluid heat exchangers, is contained inapplicant's corresponding published application WO 03/007372, dated Jan.23, 2003 and is incorporated herein by reference.

SUMMARY

In accordance with another broad aspect of the present invention, thereis provided a fluid heat exchanger comprising: a base, a heat pipeincluding an evaporator portion thermally coupled to the base and acondenser portion; a coolant block portion thermally coupled to thecondenser portion of the heat pipe, the coolant block portion includinga liquid tight passage extending from a passage inlet to a passageoutlet.

In accordance with another broad aspect of the present invention, thereis provided a cooling system for a heat-generating component, thecooling system comprising: a fluid heat exchanger including a base, aheat pipe including an evaporator portion thermally coupled to the baseand a condenser portion; a coolant block portion thermally coupled tothe condenser portion of the heat pipe, the coolant block portionincluding a liquid tight passage extending from a passage inlet to apassage outlet.

It is to be understood that other aspects of the present invention willbecome readily apparent to those skilled in the art from the followingdetailed description, wherein various embodiments of the invention areshown and described by way of illustration. As will be realized, theinvention is capable for other and different embodiments and its severaldetails are capable of modification in various other respects, allwithout departing from the spirit and scope of the present invention.Accordingly the drawings and detailed description are to be regarded asillustrative in nature and not as restrictive.

DESCRIPTION OF THE DRAWINGS

Referring to the drawings wherein like reference numerals indicatesimilar parts throughout the several views, several aspects of thepresent invention are illustrated by way of example, and not by way oflimitation, in detail in the figures, wherein:

FIG. 1 is a side elevation of an assembled fluid heat exchanger.

FIG. 2 is an end elevation of the fluid heat exchanger of FIG. 1.

FIG. 3 is a bottom plan view of the fluid heat exchanger of FIG. 1.

FIG. 4 is a top plan view of a fluid heat exchanger base and heat pipeswith the coolant block portion removed.

FIG. 5 is a side elevation of the assembly of FIG. 4.

FIG. 6 is a schematic view of a cooling system for a heat-generatingcomponent.

DESCRIPTION OF THE VARIOUS EMBODIMENTS

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various embodiments of thepresent invention and is not intended to represent the only embodimentscontemplated by the inventor. The detailed description includes specificdetails for the purpose of providing a comprehensive understanding ofthe present invention. However, it will be apparent to those skilled inthe art that the present invention may be practiced without thesespecific details.

Referring to FIGS. 1 to 5, a fluid heat exchanger 10 is shown thatincludes a base 12, a coolant block portion 14 and one or more heatpipes 16, each heat pipe including an evaporator portion 18 and acondenser portion 20. The evaporator portion of each heat pipe isattached and thermally coupled to the base and the condenser portion ofeach heat pipe is attached and thermally coupled to coolant blockportion 14.

It is to be understood that fluid heat exchanger 10 may be used toconduct heat away from a heat-generating component such as, for example,a component of a computer or other electric or electronic device. Inoperation, base 12 is mounted in thermal communication with the heatgenerating component and heat is conveyed through base 12 to the heatpipes 16 and then to coolant block portion 14 where the heat isdissipated to a liquid coolant medium for further conveyance out of thefluid heat exchanger.

Base 12 may be formed in various ways and of various materials to permitmounting to accept heat energy from the heat generating component, toconduct thermal energy and to accept, support and be in thermalcommunication with heat pipes 16. The heat pipes may be thermallycoupled to and/or arranged relative to base 12 in various ways. In theillustrated embodiment, base 12 is formed about a portion of each heatpipe 16, which portion thereby becomes the evaporator portion 18 of eachheat pipe. To enhance operation of the heat exchanger, base 12 and heatpipe evaporator portions 18 may be formed and/or arranged such thatelongate portions of the heat pipes pass through the base. For examplebase 12 may include an elongate dimension along which the heat pipesextend and are thermally coupled.

It will be appreciated that a heat pipe operates by phase change of aheat transfer, working medium between the heat pipe's evaporator portion18 and condenser portion 20. Heat pipes generally include a closedenvelope in which heat transfer working medium is contained. The heattransfer is achieved by vaporization of the working medium at theevaporator portion by action of received heat energy and condensation ofthe gaseous working medium at condenser portion 20, which is cooler dueto its thermally conductive contact with portion 14 that permitsdissipation of the heat energy. A circuit is set up within a heat pipewherein working medium moves from the condenser portion to theevaporator portion by gravity flow or wicking action.

In the presently illustrated embodiment, the heat pipes are formed ashollow tubes. Heat pipes may take various forms. For example, heat pipesmay be relatively straight or curved. In one embodiment, for example,one or more of the heat pipes may be L-shaped or U-shaped including anevaporator portion and an arm, defining the condenser portion, extendingat an angle from the evaporator portion at one or both ends of theevaporator portion. The illustrated embodiment, for example, includes aheat pipe formed such that it has a first end 16′ and an opposite end16″ and the first and opposite ends define condenser portions 20, whilethe heat pipe's evaporator portion 20 is positioned along the length ofthe pipe between its ends.

While other numbers and configurations of heat pipes may be used asdesired, in the illustrated embodiment of FIGS. 4 and 5 there are threeheat pipes 16 a, 16 b, 16 c and each heat pipe includes an elongateevaporator portion (inside base 12) positioned between ends formed asheat pipe condenser portions 20 a, 20 b, 20 c. In this way, evaporatedworking medium within the heat pipe may migrate to either end of theheat pipe to convey heat energy from the base to the coolant blockportion. This may reduce the occurrence of heat pipe dry outs whichsometimes occur in environments where the heat exchanger must operationunder significant heat load. Ends 16′ 16″ may be straight upstanding orcurved. For example, in the illustrated embodiment, both ends are curvedto each include a return portion extending substantially parallel to theevaporator portion. The curved end returns are positioned in side byside relation with one end 16′ running in direction opposite to theother end 16″ such that the heat exchanger forms a compact arrangement.In the illustrated embodiment, the plurality of heat pipes define aplurality of returned ends that may be curved and positioned in side byside, spaced apart relation and coolant block portion 14 may bethermally coupled to the arranged ends 16′ 16″. The ends may be arrangedsubstantially in a plane to facilitate connection to block portion 14.In one embodiment, the planar configuration of ends 16′, 16″, portion 14and base 12 may be substantially in parallel to provide a compactarrangement.

The heat pipes may be attached to and/or arranged relative to coolantblock portion 14 in various ways. In one embodiment, a plurality ofcoolant blocks may be used into each of which at least some of the heatsink pipe condenser portions are connected and thermally coupled.Alternately, a single coolant block portion may be used. Where both endsof an elongate heat pipe are formed as condenser portions, the ends maybe configured, as by curving, to each be mounted in a single coolantblock portion 14, which may reduce the overall size of the fluid heatexchanger. To facilitate operation of the heat exchanger, the heat pipecondenser portions may be formed such that elongate portions thereof arethermally coupled to the coolant block portion.

Coolant block portion 14, in addition to its connection to heat pipes16, includes a body with one or more liquid tight passages extendingtherethrough. The passages provide for conduction of liquid coolant,such as one or more of water, a glycol, a freon, etc., from a passageinlet through the body of portion 14 to a passage outlet. Passages maybe formed in various ways and configurations through coolant blockportion 14 to permit flow of liquid coolant therethrough andheat-dissipating contact between the body of the coolant block portionand liquid coolant passing through the passages. Generally, a passagethat provides expansive contact with body is desirable. In theillustrated embodiment, coolant block portion includes a passage 22extending between barbs 24. Passage 22 is formed to contain the liquidcoolant in a liquid tight manner and channel it between the barbs. Inthe illustrated embodiment, passage 22 is formed as an open area belowan upper body cap 14 a and includes internal dividers 23 to define thepassage and channel and direct the flow of coolant through the body.

Thermal coupling between the parts may be provided by casting, welding,soldering, press fitting, thermally conductive adhesives or fillers, andmany other ways as will be apparent to a skilled person. In theillustrated embodiment, portion 14 is formed of two parts: an upper part26 including passage 22 extending therethrough and a clamping part 28that can be clamped against upper part 26 with the heat pipe condenserportions 20 secured therebetween, as by use of screws 30. Correspondinggrooves 32 may be formed in interfacing surfaces of upper part 26 andclamping part 28 to form channels into which the heat pipes may besecured. Thermally conductive fillers can be used between heat pipes 16and upper part 26. Of course, other modes of assembly and thermalcoupling can be used, as desired.

Referring to FIG. 6, a computer cooling system 100 is shown for aheat-generating component 102 of the computer. The cooling systemincludes a fluid heat exchanger 110 including a base 112, a coolantblock portion 114 and a heat pipe 116, each heat pipe including anevaporator portion 118 and a condenser portion 120. The evaporatorportion of each heat pipe is attached and thermally coupled to the baseand the condenser portion of each heat pipe is attached and thermallycoupled to coolant block portion 114. Coolant block portion 114 includesa passage 122 to channel liquid coolant in a liquid tight manner betweenan inlet 124 a and an outlet 124 b.

Fluid heat exchanger 110 is included in the system to conduct heat awayfrom heat generating component 102. To do so, base 112 is mounted inthermal communication with heat generating component 102 and heat isconveyed through base 112 to the heat pipes 116 and then to coolantblock portion 114 where the heat is dissipated to a liquid coolantmedium passing through passage 122 for further conveyance out of thefluid heat exchanger.

In the system, an inlet tube 140 may be connectable to inlet 124 a andan outlet tube 142 may be connectable to outlet 124 b to conduct theliquid coolant in a circuit between a heat sink 144 and coolant blockportion 114. The respective connections between inlet tube 140 and inlet124 a and between outlet tube 142 and outlet 124 b may be liquid tightto avoid leakage of liquid coolant at these connection points.

The previous description of the disclosed embodiments is provided toenable any person skilled in the art to make or use the presentinvention. Various modifications to those embodiments will be readilyapparent to those skilled in the art, and the generic principles definedherein may be applied to other embodiments without departing from thespirit or scope of the invention. Thus, the present invention is notintended to be limited to the embodiments shown herein, but is to beaccorded the full scope consistent with the claims, wherein reference toan element in the singular, such as by use of the article “a” or “an” isnot intended to mean “one and only one” unless specifically so stated,but rather “one or more”. All structural and functional equivalents tothe elements of the various embodiments described throughout thedisclosure that are know or later come to be known to those of ordinaryskill in the art are intended to be encompassed by the elements of theclaims. Moreover, nothing disclosed herein is intended to be dedicatedto the public regardless of whether such disclosure is explicitlyrecited in the claims. No claim element is to be construed under theprovisions of 35 USC 112, sixth paragraph, unless the element isexpressly recited using the phrase “means for” or “step for”.

1. A fluid heat exchanger comprising: a base, a heat pipe including anevaporator portion thermally coupled to the base and a condenserportion; a coolant block portion thermally coupled to the condenserportion of the heat pipe, the coolant block portion including a liquidtight passage extending from a passage inlet to a passage outlet.
 2. Thefluid heat exchanger of claim 1 wherein the passage inlet is formed as abarb.
 3. The fluid heat exchanger of claim 1 wherein the passage outletis formed as a barb.
 4. The fluid heat exchanger of claim 1 furthercomprising internal dividers defining the liquid tight passage.
 5. Thefluid heat exchanger of claim 1 wherein the heat pipe includes anelongate return thermally coupled to the coolant block.
 6. The fluidheat exchanger of claim 1 wherein the coolant block portion includes anupper portion and a clamping portion and the condenser portion of theheat pipe is clamped between the upper portion and the clamping portion.7. A cooling system for a heat-generating component, the cooling systemcomprising: a fluid heat exchanger including a base, a heat pipeincluding an evaporator portion thermally coupled to the base and acondenser portion; a coolant block portion thermally coupled to thecondenser portion of the heat pipe, the coolant block portion includinga liquid tight passage extending from a passage inlet to a passageoutlet.
 8. The cooling system of claim 7 further comprising a liquidcoolant inlet tube connectable at the passage inlet.
 9. The coolingsystem of claim 7 further comprising a liquid coolant outlet tubeconnectable at the passage outlet.
 10. The cooling system of claim 7further comprising a liquid coolant circuit in which the fluid heatexchanger is connected.
 11. The cooling system of claim 10 wherein theliquid coolant circuit includes a liquid coolant inlet tube connected atthe passage inlet, a liquid coolant outlet tube connected at the passageoutlet and a heat sink connected between the liquid coolant outlet tubeand the liquid coolant outlet tube.
 12. The cooling system of claim 7wherein the passage inlet is formed as a barb.
 13. The cooling system ofclaim 7 wherein the passage outlet is formed as a barb.
 14. The coolingsystem of claim 7 further comprising internal dividers defining theliquid tight passage.
 15. The cooling system of claim 7 wherein the heatpipe includes an elongate return thermally coupled to the coolant block.16. The cooling system of claim 7 wherein the coolant block portionincludes an upper portion and a clamping portion and the condenserportion of the heat pipe is clamped between the upper portion and theclamping portion.